Ouch! The Environmental Cost of Free Parking. {Infographic}

Photo from pinterest.

As a driver, you may think the biggest problem with parking is how expensive it is, or how scarce. But beyond those inconveniences, city planners and environmentalists see a graver set of issues.

Sixty years of carving out space for America’s 250 million on-road vehicles has made parking—a broad category of infrastructure that includes street parking, garages, and parking lots —the “single biggest land use in any city.”

~ UCLA’s Donald Shoup.

Think about that—all in all, parking takes up more space than buildings, parks, or industrial complexes. Any infrastructure of this magnitude will inevitably generate significant economic, ecological, and urban-design consequences for the surrounding area.

So what’s going on behind the scenes as your Prius awaits your return? You might not like it.

This infographic from My Parking Sign tells the story.

Click here to view a larger image

Listen to the podcast on the subject with Donald Shoup, Distinguished Professor of Urban Planning at UCLA, where he has served as Chair of the Department of Urban Planning and Director of the Institute of Transportation Studies.  He’s been examining parking systems for the better part of thirty years, and his seminal book, The High Cost of Free Parking, is considered by many to be the last word on how America’s parking is broken, and what steps we might take to fix it.

Here, a nuts-and-bolts breakdown of the problems with different parking typologies.

Parking garages

Parking garages, multi-level structures usually built in denser urban areas, are designed to house many cars in a relatively compact space. Garages are “very expensive to build,” says Donald Shoup, because of the prime urban real estate, building permits, and building materials they require.  Maintenance costs for garages are also high. As such, they are usually built not “because developers think they’ll make money,” but in order to satisfy minimum parking standards that most cities require by law. They also have among the highest vacancy rates of any parking infrastructure. However, because most garages are open-air and compact, they are friendlier to the environment than other urban forms of parking.

Cost per space (annual): $1,265 (suburban), $1,598 (urban), $2,645 (urban, underground)

Average occupancy rate: 50-75 percent

Environmental impact: Because they are open-air and high-density, garages are greener than other parking modes. However, they also contribute to urban heat islands and often use a lot of electricity because of lighting-level requirements, during both day and night.

Design issues: The Urbanist writes that according to the conventional wisdom, parking garages should “‘blend in’ or ‘minimize their impacts’ on surrounding urban fabrics. [They are] a necessary evil, far superior to surface parking in terms of both urban form and efficiency” and should be designed “with the lessons of context and human scale still internalized….If we’re going to build housing for cars, let’s first do no harm. Then, strive to make things of beauty.”

On-street parking

“On-street parking uses less land per space than off-street parking,” because it requires no driveway, says Victoria, B.C.-based transportation planner Todd Litman. “But the land it uses often has a high opportunity cost” — precluding other types of infrastructure such as bike paths, traffic lanes, wider sidewalks, and landscaping. In addition, because street parking is often free or low-cost, and limited in quantity, vacancies are usually few. This high occupancy rate and low cost leads drivers to “doggedly search for a free curb space” (rather than pay for a garage space) — a phenomenon known as cruising.

Cost per space (annual): $408 (suburban), $578 (urban)[19]

Average occupancy rate: Highly variable depending on the city. Cities actively managing their parking strive for 85% daytime occupancy; without management, downtown occupancy often reaches 100%. At night, vacancies can be 50% or above.[20]

Environmental Impact: Cruising — the practice of circling the block until a spot opens up — has serious environmental impacts. Because it can add, on average, 10.6 stop-and-go minutes (in New York City)[21] to 11.5 minutes (in Cambridge, Mass., ibid) to the time of each journey, it increases air pollution in cities.

Design issues: Badly managed street parking that leads to cruising also contributes to increased traffic in downtowns. Shoup finds that at any given time in cities around America, between 8 and 74 percent of total cars on the road are simply looking for parking.[22]

Surface lots

“Surface lots are cheap to build,” with the lowest per-space cost of any parking typology, says Eran Ben-Joseph. That made them a popular choice for developers and municipalities during the suburban boom and resulting urban decline of the 1950s through 1970s. Today, sprawling surface parking commonly surrounds malls and office parks, and blocks of downtown real estate are occupied by paved lots. The proliferation of surface lots in and outside cities has had profound environmental and urban-design impacts on the country.

Cost per space (annual): $408 (suburban, shopping area); $780 (urban)

Average occupancy rate: 35-45 percent (suburban, shopping area; urban areas vary widely. One study found that occupancy rates in Iowa City, IA averaged 36%, and only reached 74% during the busiest days of shopping just before Christmas.

Environmental impact:

• Runoff. Impermeable surfaces like pavement increase stormwater volume and speed — a combination known as “runoff” — up to 16 times over a similarly sized meadow. Runoff not only physically reconfigures the shape and velocity of streambeds (bad for fish and vegetation), it also introduces oil, metals, and soils into waterways and prevents the recharge of aquifers (bad for our potable water supply). In large metropolitan areas, unsustainable parking lot design may be responsible for up to 132.8 billion gallons of waste water each year (enough to supply 3.6 million American households).
• Heat island effect. Replacing natural vegetation with parking lots also results in increased temperatures for the surrounding area. Because of its dark color and low moisture content, asphalt captures and retains excessive heat, making lots up to 30 degrees hotter than other surfaces. This “heat island” effect creates higher demand for air conditioning in surrounding buildings, among other impacts.
• Light pollution. Lighting engineers often make parking lots very bright to increase safety at night. However, this “radiating obtrusive light… tends to wash out the darkness low in the sky and trespass on neighboring properties,” writes Ben-Joseph.

Design issues:

• Pensacola Parking Syndrome. Urban surface lots are often blamed for clinching the decline of the American downtown after suburbanization in the 1960s. Writes Ben-Joseph in Rethinking A Lot, “In the mid-twentieth century, downtown central business districts tried to compete with suburban shopping centers by tearing down dilapidated buildings and turning them into parking lots.” As planners tried to entice visitors back downtown, parking lots — hardly an inviting feature — often became the most salient aspect of the inner city. By the 1970s, for example, 74 percent of Detroit’s downtown had been turned over to cars. Even today, nearly one-third of the central business district in Orlando, Fla., is covered in asphalt.
• Asphalt seas. In retail areas, developers build parking lots to accommodate the massive crowds expected on the busiest shopping day of the year (Black Friday). As a result, malls and big-box stores are surrounded by acre upon acre of paved land (for a two-story building, 80% of a site must be set aside for surface parking, says Ben-Joseph). This creates a land-use pattern in which individual buildings are surrounded by seas of asphalt, a low-density design that makes pedestrianism nearly impossible and contributes to suburban sprawl.

Safety concerns: Parking lots and garages must be designed to minimize the possibility that pedestrians will be struck by a vehicle; create an environment that deters criminal behavior because perpetrators feel they will be seen; and minimize tripping hazards (snow buildup, ice, oil spots, etc.) through proper maintenance. When these conditions are not met, the owner of a parking facility may be liable.

• The U.S. is oversupplied with free parking due to disorganized and sometimes ill-informed municipal planning practices, resulting in wasted land and resources.
• The market value of America’s parking is over $310 billion, but only a tiny percentage of its costs are ever recouped directly.
• As a response to the surprisingly high expense of providing free parking, many lot owners and lessees are beginning to adopt permit systems, allowing them to recover some of the costs of their parking.
• At the same time, the top-10-selling parking signs occupy a smaller and smaller portion of sales, indicating public demand for more varied organizational systems than before.

[Source: My Parking Sign]